#include "duckdb/common/local_file_system.hpp"

#include "duckdb/common/checksum.hpp"
#include "duckdb/common/exception.hpp"
#include "duckdb/common/file_opener.hpp"
#include "duckdb/common/helper.hpp"
#include "duckdb/common/string_util.hpp"
#include "duckdb/common/windows.hpp"
#include "duckdb/function/scalar/string_common.hpp"
#include "duckdb/main/client_context.hpp"
#include "duckdb/main/database.hpp"

#include <cstdint>
#include <cstdio>
#include <sys/stat.h>

#ifndef _WIN32
#include <dirent.h>
#include <fcntl.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#else
#include "duckdb/common/windows_util.hpp"

#include <io.h>
#include <string>

#ifdef __MINGW32__
// need to manually define this for mingw
extern "C" WINBASEAPI BOOL WINAPI GetPhysicallyInstalledSystemMemory(PULONGLONG);
extern "C" WINBASEAPI BOOL QueryFullProcessImageNameW(HANDLE, DWORD, LPWSTR, PDWORD);
#endif

#undef FILE_CREATE // woo mingw
#endif

// includes for giving a better error message on lock conflicts
#if defined(__linux__) || defined(__APPLE__)
#include <pwd.h>
#endif

#if defined(__linux__)
// See https://man7.org/linux/man-pages/man2/fallocate.2.html
#ifndef _GNU_SOURCE
#define _GNU_SOURCE /* See feature_test_macros(7) */
#endif
#include <fcntl.h>
#include <libgen.h>
// See e.g.:
// https://opensource.apple.com/source/CarbonHeaders/CarbonHeaders-18.1/TargetConditionals.h.auto.html
#elif defined(__APPLE__)
#include <TargetConditionals.h>
#if not(defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE == 1)
#include <libproc.h>
#endif
#elif defined(_WIN32)
#include <restartmanager.h>
#endif

namespace duckdb {
#ifndef _WIN32
bool LocalFileSystem::FileExists(const string &filename, optional_ptr<FileOpener> opener) {
	if (!filename.empty()) {
		auto normalized_file = NormalizeLocalPath(filename);
		if (access(normalized_file, 0) == 0) {
			struct stat status;
			stat(normalized_file, &status);
			if (S_ISREG(status.st_mode)) {
				return true;
			}
		}
	}
	// if any condition fails
	return false;
}

bool LocalFileSystem::IsPipe(const string &filename, optional_ptr<FileOpener> opener) {
	if (!filename.empty()) {
		auto normalized_file = NormalizeLocalPath(filename);
		if (access(normalized_file, 0) == 0) {
			struct stat status;
			stat(normalized_file, &status);
			if (S_ISFIFO(status.st_mode)) {
				return true;
			}
		}
	}
	// if any condition fails
	return false;
}

#else
static std::wstring NormalizePathAndConvertToUnicode(const string &path) {
	string normalized_path_copy;
	const char *normalized_path;
	if (StringUtil::StartsWith(path, "file:/")) {
		normalized_path_copy = LocalFileSystem::NormalizeLocalPath(path);
		normalized_path_copy = LocalFileSystem().ConvertSeparators(normalized_path_copy);
		normalized_path = normalized_path_copy.c_str();
	} else {
		normalized_path = path.c_str();
	}
	return WindowsUtil::UTF8ToUnicode(normalized_path);
}

bool LocalFileSystem::FileExists(const string &filename, optional_ptr<FileOpener> opener) {
	auto unicode_path = NormalizePathAndConvertToUnicode(filename);
	const wchar_t *wpath = unicode_path.c_str();
	if (_waccess(wpath, 0) == 0) {
		struct _stati64 status;
		_wstati64(wpath, &status);
		if (status.st_mode & S_IFREG) {
			return true;
		}
	}
	return false;
}
bool LocalFileSystem::IsPipe(const string &filename, optional_ptr<FileOpener> opener) {
	auto unicode_path = NormalizePathAndConvertToUnicode(filename);
	const wchar_t *wpath = unicode_path.c_str();
	if (_waccess(wpath, 0) == 0) {
		struct _stati64 status;
		_wstati64(wpath, &status);
		if (status.st_mode & _S_IFCHR) {
			return true;
		}
	}
	return false;
}
#endif

#ifndef _WIN32
// somehow sometimes this is missing
#ifndef O_CLOEXEC
#define O_CLOEXEC 0
#endif

// Solaris
#ifndef O_DIRECT
#define O_DIRECT 0
#endif

struct UnixFileHandle : public FileHandle {
public:
	UnixFileHandle(FileSystem &file_system, string path, int fd, FileOpenFlags flags)
	    : FileHandle(file_system, std::move(path), flags), fd(fd) {
	}
	~UnixFileHandle() override {
		UnixFileHandle::Close();
	}

	int fd;

public:
	void Close() override {
		if (fd != -1) {
			close(fd);
			fd = -1;
		}
	};
};

static FileType GetFileTypeInternal(int fd) { // LCOV_EXCL_START
	struct stat s;
	if (fstat(fd, &s) == -1) {
		return FileType::FILE_TYPE_INVALID;
	}
	switch (s.st_mode & S_IFMT) {
	case S_IFBLK:
		return FileType::FILE_TYPE_BLOCKDEV;
	case S_IFCHR:
		return FileType::FILE_TYPE_CHARDEV;
	case S_IFIFO:
		return FileType::FILE_TYPE_FIFO;
	case S_IFDIR:
		return FileType::FILE_TYPE_DIR;
	case S_IFLNK:
		return FileType::FILE_TYPE_LINK;
	case S_IFREG:
		return FileType::FILE_TYPE_REGULAR;
	case S_IFSOCK:
		return FileType::FILE_TYPE_SOCKET;
	default:
		return FileType::FILE_TYPE_INVALID;
	}
} // LCOV_EXCL_STOP

#if __APPLE__ && !TARGET_OS_IPHONE

static string AdditionalProcessInfo(FileSystem &fs, pid_t pid) {
	if (pid == getpid()) {
		return "Lock is already held in current process, likely another DuckDB instance";
	}

	string process_name, process_owner;
	// macOS >= 10.7 has PROC_PIDT_SHORTBSDINFO
#ifdef PROC_PIDT_SHORTBSDINFO
	// try to find out more about the process holding the lock
	struct proc_bsdshortinfo proc;
	if (proc_pidinfo(pid, PROC_PIDT_SHORTBSDINFO, 0, &proc, PROC_PIDT_SHORTBSDINFO_SIZE) ==
	    PROC_PIDT_SHORTBSDINFO_SIZE) {
		process_name = proc.pbsi_comm; // only a short version however, let's take it in case proc_pidpath() below fails
		// try to get actual name of conflicting process owner
		auto pw = getpwuid(proc.pbsi_uid);
		if (pw) {
			process_owner = pw->pw_name;
		}
	}
#else
	return string();
#endif
	// try to get a better process name (full path)
	char full_exec_path[PROC_PIDPATHINFO_MAXSIZE];
	if (proc_pidpath(pid, full_exec_path, PROC_PIDPATHINFO_MAXSIZE) > 0) {
		// somehow could not get the path, lets use some sensible fallback
		process_name = full_exec_path;
	}
	return StringUtil::Format("Conflicting lock is held in %s%s",
	                          !process_name.empty() ? StringUtil::Format("%s (PID %d)", process_name, pid)
	                                                : StringUtil::Format("PID %d", pid),
	                          !process_owner.empty() ? StringUtil::Format(" by user %s", process_owner) : "");
}

#elif __linux__

static string AdditionalProcessInfo(FileSystem &fs, pid_t pid) {
	if (pid == getpid()) {
		return "Lock is already held in current process, likely another DuckDB instance";
	}
	string process_name, process_owner;

	try {
		auto cmdline_file = fs.OpenFile(StringUtil::Format("/proc/%d/cmdline", pid), FileFlags::FILE_FLAGS_READ);
		auto cmdline = cmdline_file->ReadLine();
		process_name = basename(const_cast<char *>(cmdline.c_str())); // NOLINT: old C API does not take const
	} catch (std::exception &) {
		// ignore
	}

	// we would like to provide a full path to the executable if possible but we might not have rights
	{
		char exe_target[PATH_MAX];
		memset(exe_target, '\0', PATH_MAX);
		auto proc_exe_link = StringUtil::Format("/proc/%d/exe", pid);
		auto readlink_n = readlink(proc_exe_link.c_str(), exe_target, PATH_MAX);
		if (readlink_n > 0) {
			process_name = exe_target;
		}
	}

	// try to find out who created that process
	try {
		auto loginuid_file = fs.OpenFile(StringUtil::Format("/proc/%d/loginuid", pid), FileFlags::FILE_FLAGS_READ);
		auto uid = std::stoi(loginuid_file->ReadLine());
		auto pw = getpwuid(uid);
		if (pw) {
			process_owner = pw->pw_name;
		}
	} catch (std::exception &) {
		// ignore
	}

	return StringUtil::Format("Conflicting lock is held in %s%s",
	                          !process_name.empty() ? StringUtil::Format("%s (PID %d)", process_name, pid)
	                                                : StringUtil::Format("PID %d", pid),
	                          !process_owner.empty() ? StringUtil::Format(" by user %s", process_owner) : "");
}

#else
static string AdditionalProcessInfo(FileSystem &fs, pid_t pid) {
	return "";
}
#endif

bool LocalFileSystem::IsPrivateFile(const string &path_p, FileOpener *opener) {
	auto path = FileSystem::ExpandPath(path_p, opener);
	auto normalized_path = NormalizeLocalPath(path);

	struct stat st;

	if (lstat(normalized_path, &st) != 0) {
		throw IOException(
		    "Failed to stat '%s' when checking file permissions, file may be missing or have incorrect permissions",
		    path.c_str());
	}

	// If group or other have any permission, the file is not private
	if (st.st_mode & (S_IRGRP | S_IWGRP | S_IXGRP | S_IROTH | S_IWOTH | S_IXOTH)) {
		return false;
	}

	return true;
}

unique_ptr<FileHandle> LocalFileSystem::OpenFile(const string &path_p, FileOpenFlags flags,
                                                 optional_ptr<FileOpener> opener) {
	auto path = FileSystem::ExpandPath(path_p, opener);
	auto normalized_path = NormalizeLocalPath(path);
	if (flags.Compression() != FileCompressionType::UNCOMPRESSED) {
		throw NotImplementedException("Unsupported compression type for default file system");
	}

	if (opener) {
		DUCKDB_LOG_INFO(*opener, "duckdb.FileSystem.LocalFileSystem.OpenFile", path_p);
	}

	flags.Verify();

	int open_flags = 0;
	int rc;
	bool open_read = flags.OpenForReading();
	bool open_write = flags.OpenForWriting();
	if (open_read && open_write) {
		open_flags = O_RDWR;
	} else if (open_read) {
		open_flags = O_RDONLY;
	} else if (open_write) {
		open_flags = O_WRONLY;
	} else {
		throw InternalException("READ, WRITE or both should be specified when opening a file");
	}
	if (open_write) {
		// need Read or Write
		D_ASSERT(flags.OpenForWriting());
		open_flags |= O_CLOEXEC;
		if (flags.CreateFileIfNotExists()) {
			open_flags |= O_CREAT;
		} else if (flags.OverwriteExistingFile()) {
			open_flags |= O_CREAT | O_TRUNC;
		}
		if (flags.OpenForAppending()) {
			open_flags |= O_APPEND;
		}
	}
	if (flags.DirectIO()) {
#if defined(__sun) && defined(__SVR4)
		throw InvalidInputException("DIRECT_IO not supported on Solaris");
#endif
#if defined(__DARWIN__) || defined(__APPLE__) || defined(__OpenBSD__)
		// OSX does not have O_DIRECT, instead we need to use fcntl afterwards to support direct IO
#else
		open_flags |= O_DIRECT;
#endif
	}

	// Determine permissions
	mode_t filesec;
	if (flags.CreatePrivateFile()) {
		open_flags |= O_EXCL; // Ensure we error on existing files or the permissions may not set
		filesec = 0600;
	} else {
		filesec = 0666;
	}

	if (flags.ExclusiveCreate()) {
		open_flags |= O_EXCL;
	}

	// Open the file
	int fd = open(normalized_path, open_flags, filesec);

	if (fd == -1) {
		if (flags.ReturnNullIfNotExists() && errno == ENOENT) {
			return nullptr;
		}
		if (flags.ReturnNullIfExists() && errno == EEXIST) {
			return nullptr;
		}
		throw IOException("Cannot open file \"%s\": %s", {{"errno", std::to_string(errno)}}, path, strerror(errno));
	}

#if defined(__DARWIN__) || defined(__APPLE__)
	if (flags.DirectIO()) {
		// OSX requires fcntl for Direct IO
		rc = fcntl(fd, F_NOCACHE, 1);
		if (rc == -1) {
			throw IOException("Could not enable direct IO for file \"%s\": %s", path, strerror(errno));
		}
	}
#endif

	if (flags.Lock() != FileLockType::NO_LOCK) {
		// set lock on file
		// but only if it is not an input/output stream
		auto file_type = GetFileTypeInternal(fd);
		if (file_type != FileType::FILE_TYPE_FIFO && file_type != FileType::FILE_TYPE_SOCKET) {
			struct flock fl;
			memset(&fl, 0, sizeof fl);
			fl.l_type = flags.Lock() == FileLockType::READ_LOCK ? F_RDLCK : F_WRLCK;
			fl.l_whence = SEEK_SET;
			fl.l_start = 0;
			fl.l_len = 0;
			rc = fcntl(fd, F_SETLK, &fl);
			// Retain the original error.
			int retained_errno = errno;
			bool has_error = rc == -1;
			string extended_error;
			if (has_error) {
				if (retained_errno == ENOTSUP) {
					// file lock not supported for this file system
					if (flags.Lock() == FileLockType::READ_LOCK) {
						// for read-only, we ignore not-supported errors
						has_error = false;
						errno = 0;
					} else {
						extended_error = "File locks are not supported for this file system, cannot open the file in "
						                 "read-write mode. Try opening the file in read-only mode";
					}
				}
			}
			if (has_error) {
				if (extended_error.empty()) {
					// try to find out who is holding the lock using F_GETLK
					rc = fcntl(fd, F_GETLK, &fl);
					if (rc == -1) { // fnctl does not want to help us
						extended_error = strerror(errno);
					} else {
						extended_error = AdditionalProcessInfo(*this, fl.l_pid);
					}
					if (flags.Lock() == FileLockType::WRITE_LOCK) {
						// maybe we can get a read lock instead and tell this to the user.
						fl.l_type = F_RDLCK;
						rc = fcntl(fd, F_SETLK, &fl);
						if (rc != -1) { // success!
							extended_error +=
							    ". However, you would be able to open this database in read-only mode, e.g. by "
							    "using the -readonly parameter in the CLI";
						}
					}
				}
				rc = close(fd);
				if (rc == -1) {
					extended_error += ". Also, failed closing file";
				}
				extended_error += ". See also https://duckdb.org/docs/connect/concurrency";
				throw IOException("Could not set lock on file \"%s\": %s", {{"errno", std::to_string(retained_errno)}},
				                  path, extended_error);
			}
		}
	}
	return make_uniq<UnixFileHandle>(*this, path, fd, flags);
}

void LocalFileSystem::SetFilePointer(FileHandle &handle, idx_t location) {
	int fd = handle.Cast<UnixFileHandle>().fd;
	off_t offset = lseek(fd, UnsafeNumericCast<off_t>(location), SEEK_SET);
	if (offset == (off_t)-1) {
		throw IOException("Could not seek to location %lld for file \"%s\": %s", {{"errno", std::to_string(errno)}},
		                  location, handle.path, strerror(errno));
	}
}

idx_t LocalFileSystem::GetFilePointer(FileHandle &handle) {
	int fd = handle.Cast<UnixFileHandle>().fd;
	off_t position = lseek(fd, 0, SEEK_CUR);
	if (position == (off_t)-1) {
		throw IOException("Could not get file position file \"%s\": %s", {{"errno", std::to_string(errno)}},
		                  handle.path, strerror(errno));
	}
	return UnsafeNumericCast<idx_t>(position);
}

void LocalFileSystem::Read(FileHandle &handle, void *buffer, int64_t nr_bytes, idx_t location) {
	int fd = handle.Cast<UnixFileHandle>().fd;
	auto read_buffer = char_ptr_cast(buffer);
	while (nr_bytes > 0) {
		int64_t bytes_read =
		    pread(fd, read_buffer, UnsafeNumericCast<size_t>(nr_bytes), UnsafeNumericCast<off_t>(location));
		if (bytes_read == -1) {
			throw IOException("Could not read from file \"%s\": %s", {{"errno", std::to_string(errno)}}, handle.path,
			                  strerror(errno));
		}
		if (bytes_read == 0) {
			throw IOException(
			    "Could not read enough bytes from file \"%s\": attempted to read %llu bytes from location %llu",
			    handle.path, nr_bytes, location);
		}
		read_buffer += bytes_read;
		nr_bytes -= bytes_read;
		location += UnsafeNumericCast<idx_t>(bytes_read);
	}
}

int64_t LocalFileSystem::Read(FileHandle &handle, void *buffer, int64_t nr_bytes) {
	int fd = handle.Cast<UnixFileHandle>().fd;
	int64_t bytes_read = read(fd, buffer, UnsafeNumericCast<size_t>(nr_bytes));
	if (bytes_read == -1) {
		throw IOException("Could not read from file \"%s\": %s", {{"errno", std::to_string(errno)}}, handle.path,
		                  strerror(errno));
	}
	return bytes_read;
}

void LocalFileSystem::Write(FileHandle &handle, void *buffer, int64_t nr_bytes, idx_t location) {
	int fd = handle.Cast<UnixFileHandle>().fd;
	auto write_buffer = char_ptr_cast(buffer);
	while (nr_bytes > 0) {
		int64_t bytes_written =
		    pwrite(fd, write_buffer, UnsafeNumericCast<size_t>(nr_bytes), UnsafeNumericCast<off_t>(location));
		if (bytes_written < 0) {
			throw IOException("Could not write file \"%s\": %s", {{"errno", std::to_string(errno)}}, handle.path,
			                  strerror(errno));
		}
		if (bytes_written == 0) {
			throw IOException("Could not write to file \"%s\" - attempted to write 0 bytes: %s",
			                  {{"errno", std::to_string(errno)}}, handle.path, strerror(errno));
		}
		write_buffer += bytes_written;
		nr_bytes -= bytes_written;
		location += UnsafeNumericCast<idx_t>(bytes_written);
	}
}

int64_t LocalFileSystem::Write(FileHandle &handle, void *buffer, int64_t nr_bytes) {
	int fd = handle.Cast<UnixFileHandle>().fd;
	int64_t bytes_written = 0;
	while (nr_bytes > 0) {
		auto bytes_to_write = MinValue<idx_t>(idx_t(NumericLimits<int32_t>::Maximum()), idx_t(nr_bytes));
		int64_t current_bytes_written = write(fd, buffer, bytes_to_write);
		if (current_bytes_written <= 0) {
			throw IOException("Could not write file \"%s\": %s", {{"errno", std::to_string(errno)}}, handle.path,
			                  strerror(errno));
		}
		bytes_written += current_bytes_written;
		buffer = (void *)(data_ptr_cast(buffer) + current_bytes_written);
		nr_bytes -= current_bytes_written;
	}
	return bytes_written;
}

bool LocalFileSystem::Trim(FileHandle &handle, idx_t offset_bytes, idx_t length_bytes) {
#if defined(__linux__)
	// FALLOC_FL_PUNCH_HOLE requires glibc 2.18 or up
#if __GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ < 18)
	return false;
#else
	int fd = handle.Cast<UnixFileHandle>().fd;
	int res = fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, UnsafeNumericCast<int64_t>(offset_bytes),
	                    UnsafeNumericCast<int64_t>(length_bytes));
	return res == 0;
#endif
#else
	return false;
#endif
}

int64_t LocalFileSystem::GetFileSize(FileHandle &handle) {
	int fd = handle.Cast<UnixFileHandle>().fd;
	struct stat s;
	if (fstat(fd, &s) == -1) {
		throw IOException("Failed to get file size for file \"%s\": %s", {{"errno", std::to_string(errno)}},
		                  handle.path, strerror(errno));
	}
	return s.st_size;
}

time_t LocalFileSystem::GetLastModifiedTime(FileHandle &handle) {
	int fd = handle.Cast<UnixFileHandle>().fd;
	struct stat s;
	if (fstat(fd, &s) == -1) {
		throw IOException("Failed to get last modified time for file \"%s\": %s", {{"errno", std::to_string(errno)}},
		                  handle.path, strerror(errno));
	}
	return s.st_mtime;
}

FileType LocalFileSystem::GetFileType(FileHandle &handle) {
	int fd = handle.Cast<UnixFileHandle>().fd;
	return GetFileTypeInternal(fd);
}

void LocalFileSystem::Truncate(FileHandle &handle, int64_t new_size) {
	int fd = handle.Cast<UnixFileHandle>().fd;
	if (ftruncate(fd, new_size) != 0) {
		throw IOException("Could not truncate file \"%s\": %s", {{"errno", std::to_string(errno)}}, handle.path,
		                  strerror(errno));
	}
}

bool LocalFileSystem::DirectoryExists(const string &directory, optional_ptr<FileOpener> opener) {
	if (!directory.empty()) {
		auto normalized_dir = NormalizeLocalPath(directory);
		if (access(normalized_dir, 0) == 0) {
			struct stat status;
			stat(normalized_dir, &status);
			if (status.st_mode & S_IFDIR) {
				return true;
			}
		}
	}
	// if any condition fails
	return false;
}

void LocalFileSystem::CreateDirectory(const string &directory, optional_ptr<FileOpener> opener) {
	struct stat st;

	auto normalized_dir = NormalizeLocalPath(directory);
	if (stat(normalized_dir, &st) != 0) {
		/* Directory does not exist. EEXIST for race condition */
		if (mkdir(normalized_dir, 0755) != 0 && errno != EEXIST) {
			throw IOException("Failed to create directory \"%s\": %s", {{"errno", std::to_string(errno)}}, directory,
			                  strerror(errno));
		}
	} else if (!S_ISDIR(st.st_mode)) {
		throw IOException("Failed to create directory \"%s\": path exists but is not a directory!",
		                  {{"errno", std::to_string(errno)}}, directory);
	}
}

int RemoveDirectoryRecursive(const char *path) {
	DIR *d = opendir(path);
	idx_t path_len = (idx_t)strlen(path);
	int r = -1;

	if (d) {
		struct dirent *p;
		r = 0;
		while (!r && (p = readdir(d))) {
			int r2 = -1;
			char *buf;
			idx_t len;
			/* Skip the names "." and ".." as we don't want to recurse on them. */
			if (!strcmp(p->d_name, ".") || !strcmp(p->d_name, "..")) {
				continue;
			}
			len = path_len + (idx_t)strlen(p->d_name) + 2;
			buf = new (std::nothrow) char[len];
			if (buf) {
				struct stat statbuf;
				snprintf(buf, len, "%s/%s", path, p->d_name);
				if (!stat(buf, &statbuf)) {
					if (S_ISDIR(statbuf.st_mode)) {
						r2 = RemoveDirectoryRecursive(buf);
					} else {
						r2 = unlink(buf);
					}
				}
				delete[] buf;
			}
			r = r2;
		}
		closedir(d);
	}
	if (!r) {
		r = rmdir(path);
	}
	return r;
}

void LocalFileSystem::RemoveDirectory(const string &directory, optional_ptr<FileOpener> opener) {
	auto normalized_dir = NormalizeLocalPath(directory);
	RemoveDirectoryRecursive(normalized_dir);
}

void LocalFileSystem::RemoveFile(const string &filename, optional_ptr<FileOpener> opener) {
	auto normalized_file = NormalizeLocalPath(filename);
	if (std::remove(normalized_file) != 0) {
		throw IOException("Could not remove file \"%s\": %s", {{"errno", std::to_string(errno)}}, filename,
		                  strerror(errno));
	}
}

bool LocalFileSystem::ListFiles(const string &directory, const std::function<void(const string &, bool)> &callback,
                                FileOpener *opener) {
	auto normalized_dir = NormalizeLocalPath(directory);
	auto dir = opendir(normalized_dir);
	if (!dir) {
		return false;
	}

	// RAII wrapper around DIR to automatically free on exceptions in callback
	std::unique_ptr<DIR, std::function<void(DIR *)>> dir_unique_ptr(dir, [](DIR *d) { closedir(d); });

	struct dirent *ent;
	// loop over all files in the directory
	while ((ent = readdir(dir)) != nullptr) {
		string name = string(ent->d_name);
		// skip . .. and empty files
		if (name.empty() || name == "." || name == "..") {
			continue;
		}
		// now stat the file to figure out if it is a regular file or directory
		string full_path = JoinPath(normalized_dir, name);
		struct stat status;
		auto res = stat(full_path.c_str(), &status);
		if (res != 0) {
			continue;
		}
		if (!(status.st_mode & S_IFREG) && !(status.st_mode & S_IFDIR)) {
			// not a file or directory: skip
			continue;
		}
		// invoke callback
		callback(name, status.st_mode & S_IFDIR);
	}

	return true;
}

void LocalFileSystem::FileSync(FileHandle &handle) {
	int fd = handle.Cast<UnixFileHandle>().fd;
	if (fsync(fd) != 0) {
		throw FatalException("fsync failed!");
	}
}

void LocalFileSystem::MoveFile(const string &source, const string &target, optional_ptr<FileOpener> opener) {
	auto normalized_source = NormalizeLocalPath(source);
	auto normalized_target = NormalizeLocalPath(target);
	//! FIXME: rename does not guarantee atomicity or overwriting target file if it exists
	if (rename(normalized_source, normalized_target) != 0) {
		throw IOException("Could not rename file!", {{"errno", std::to_string(errno)}});
	}
}

std::string LocalFileSystem::GetLastErrorAsString() {
	return string();
}

#else

constexpr char PIPE_PREFIX[] = "\\\\.\\pipe\\";

// Returns the last Win32 error, in string format. Returns an empty string if there is no error.
std::string LocalFileSystem::GetLastErrorAsString() {
	// Get the error message, if any.
	DWORD errorMessageID = GetLastError();
	if (errorMessageID == 0)
		return std::string(); // No error message has been recorded

	LPSTR messageBuffer = nullptr;
	idx_t size =
	    FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
	                   NULL, errorMessageID, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPSTR)&messageBuffer, 0, NULL);

	std::string message(messageBuffer, size);

	// Free the buffer.
	LocalFree(messageBuffer);

	return message;
}

struct WindowsFileHandle : public FileHandle {
public:
	WindowsFileHandle(FileSystem &file_system, string path, HANDLE fd, FileOpenFlags flags)
	    : FileHandle(file_system, path, flags), position(0), fd(fd) {
	}
	~WindowsFileHandle() override {
		Close();
	}

	idx_t position;
	HANDLE fd;

public:
	void Close() override {
		if (!fd) {
			return;
		}
		CloseHandle(fd);
		fd = nullptr;
	};
};

static string AdditionalLockInfo(const std::wstring path) {
	// try to find out if another process is holding the lock

	// init of the somewhat obscure "Windows Restart Manager"
	// see also https://devblogs.microsoft.com/oldnewthing/20120217-00/?p=8283

	DWORD session, status, reason;
	WCHAR session_key[CCH_RM_SESSION_KEY + 1] = {0};

	status = RmStartSession(&session, 0, session_key);
	if (status != ERROR_SUCCESS) {
		return "";
	}

	PCWSTR path_ptr = path.c_str();
	status = RmRegisterResources(session, 1, &path_ptr, 0, NULL, 0, NULL);
	if (status != ERROR_SUCCESS) {
		return "";
	}
	UINT process_info_size_needed, process_info_size;

	// we first call with nProcInfo = 0 to find out how much to allocate
	process_info_size = 0;
	status = RmGetList(session, &process_info_size_needed, &process_info_size, NULL, &reason);
	if (status != ERROR_MORE_DATA || process_info_size_needed == 0) {
		return "";
	}

	// allocate
	auto process_info_buffer = duckdb::unique_ptr<RM_PROCESS_INFO[]>(new RM_PROCESS_INFO[process_info_size_needed]);
	auto process_info = process_info_buffer.get();

	// now call again to get actual data
	process_info_size = process_info_size_needed;
	status = RmGetList(session, &process_info_size_needed, &process_info_size, process_info, &reason);
	if (status != ERROR_SUCCESS || process_info_size == 0) {
		return "";
	}

	string conflict_string = "File is already open in ";

	for (UINT process_idx = 0; process_idx < process_info_size; process_idx++) {
		string process_name = WindowsUtil::UnicodeToUTF8(process_info[process_idx].strAppName);
		auto pid = process_info[process_idx].Process.dwProcessId;

		// find out full path if possible
		HANDLE process = OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, FALSE, pid);
		if (process) {
			WCHAR full_path[MAX_PATH];
			DWORD full_path_size = MAX_PATH;
			if (QueryFullProcessImageNameW(process, 0, full_path, &full_path_size) && full_path_size <= MAX_PATH) {
				process_name = WindowsUtil::UnicodeToUTF8(full_path);
			}
			CloseHandle(process);
		}
		conflict_string += StringUtil::Format("\n%s (PID %d)", process_name, pid);
	}

	RmEndSession(session);
	return conflict_string;
}

bool LocalFileSystem::IsPrivateFile(const string &path_p, FileOpener *opener) {
	// TODO: detect if file is shared in windows
	return true;
}

unique_ptr<FileHandle> LocalFileSystem::OpenFile(const string &path_p, FileOpenFlags flags,
                                                 optional_ptr<FileOpener> opener) {
	auto path = FileSystem::ExpandPath(path_p, opener);
	auto unicode_path = NormalizePathAndConvertToUnicode(path);
	if (flags.Compression() != FileCompressionType::UNCOMPRESSED) {
		throw NotImplementedException("Unsupported compression type for default file system");
	}
	flags.Verify();

	if (opener) {
		DUCKDB_LOG_INFO(*opener, "duckdb.FileSystem.LocalFileSystem.OpenFile", path_p);
	}

	DWORD desired_access;
	DWORD share_mode;
	DWORD creation_disposition = OPEN_EXISTING;
	DWORD flags_and_attributes = FILE_ATTRIBUTE_NORMAL;
	bool open_read = flags.OpenForReading();
	bool open_write = flags.OpenForWriting();
	if (open_read && open_write) {
		desired_access = GENERIC_READ | GENERIC_WRITE;
	} else if (open_read) {
		desired_access = GENERIC_READ;
	} else if (open_write) {
		desired_access = GENERIC_WRITE;
	} else {
		throw InternalException("READ, WRITE or both should be specified when opening a file");
	}
	switch (flags.Lock()) {
	case FileLockType::NO_LOCK:
		share_mode = FILE_SHARE_READ | FILE_SHARE_WRITE;
		break;
	case FileLockType::READ_LOCK:
		share_mode = FILE_SHARE_READ;
		break;
	case FileLockType::WRITE_LOCK:
		share_mode = 0;
		break;
	default:
		throw InternalException("Unknown FileLockType");
	}

	if (open_write) {
		if (flags.CreateFileIfNotExists()) {
			creation_disposition = OPEN_ALWAYS;
		} else if (flags.OverwriteExistingFile()) {
			creation_disposition = CREATE_ALWAYS;
		}
	}
	if (flags.DirectIO()) {
		flags_and_attributes |= FILE_FLAG_NO_BUFFERING;
	}
	HANDLE hFile = CreateFileW(unicode_path.c_str(), desired_access, share_mode, NULL, creation_disposition,
	                           flags_and_attributes, NULL);
	if (hFile == INVALID_HANDLE_VALUE) {
		if (flags.ReturnNullIfNotExists() && GetLastError() == ERROR_FILE_NOT_FOUND) {
			return nullptr;
		}
		auto error = LocalFileSystem::GetLastErrorAsString();

		auto better_error = AdditionalLockInfo(unicode_path);
		if (!better_error.empty()) {
			throw IOException(better_error);
		} else {
			throw IOException("Cannot open file \"%s\": %s", path.c_str(), error);
		}
	}
	auto handle = make_uniq<WindowsFileHandle>(*this, path.c_str(), hFile, flags);
	if (flags.OpenForAppending()) {
		auto file_size = GetFileSize(*handle);
		SetFilePointer(*handle, file_size);
	}
	return std::move(handle);
}

void LocalFileSystem::SetFilePointer(FileHandle &handle, idx_t location) {
	auto &whandle = handle.Cast<WindowsFileHandle>();
	whandle.position = location;
	LARGE_INTEGER wlocation;
	wlocation.QuadPart = location;
	SetFilePointerEx(whandle.fd, wlocation, NULL, FILE_BEGIN);
}

idx_t LocalFileSystem::GetFilePointer(FileHandle &handle) {
	return handle.Cast<WindowsFileHandle>().position;
}

static DWORD FSInternalRead(FileHandle &handle, HANDLE hFile, void *buffer, int64_t nr_bytes, idx_t location) {
	DWORD bytes_read = 0;
	OVERLAPPED ov = {};
	ov.Internal = 0;
	ov.InternalHigh = 0;
	ov.Offset = location & 0xFFFFFFFF;
	ov.OffsetHigh = location >> 32;
	ov.hEvent = 0;
	auto rc = ReadFile(hFile, buffer, (DWORD)nr_bytes, &bytes_read, &ov);
	if (!rc) {
		auto error = LocalFileSystem::GetLastErrorAsString();
		throw IOException("Could not read file \"%s\" (error in ReadFile(location: %llu, nr_bytes: %lld)): %s",
		                  handle.path, location, nr_bytes, error);
	}
	return bytes_read;
}

void LocalFileSystem::Read(FileHandle &handle, void *buffer, int64_t nr_bytes, idx_t location) {
	HANDLE hFile = ((WindowsFileHandle &)handle).fd;
	auto bytes_read = FSInternalRead(handle, hFile, buffer, nr_bytes, location);
	if (bytes_read != nr_bytes) {
		throw IOException("Could not read all bytes from file \"%s\": wanted=%lld read=%lld", handle.path, nr_bytes,
		                  bytes_read);
	}
}

int64_t LocalFileSystem::Read(FileHandle &handle, void *buffer, int64_t nr_bytes) {
	HANDLE hFile = handle.Cast<WindowsFileHandle>().fd;
	auto &pos = handle.Cast<WindowsFileHandle>().position;
	auto n = std::min<idx_t>(std::max<idx_t>(GetFileSize(handle), pos) - pos, nr_bytes);
	auto bytes_read = FSInternalRead(handle, hFile, buffer, n, pos);
	pos += bytes_read;
	return bytes_read;
}

static DWORD FSInternalWrite(FileHandle &handle, HANDLE hFile, void *buffer, int64_t nr_bytes, idx_t location) {
	DWORD bytes_written = 0;
	OVERLAPPED ov = {};
	ov.Internal = 0;
	ov.InternalHigh = 0;
	ov.Offset = location & 0xFFFFFFFF;
	ov.OffsetHigh = location >> 32;
	ov.hEvent = 0;
	auto rc = WriteFile(hFile, buffer, (DWORD)nr_bytes, &bytes_written, &ov);
	if (!rc) {
		auto error = LocalFileSystem::GetLastErrorAsString();
		throw IOException("Could not write file \"%s\" (error in WriteFile): %s", handle.path, error);
	}
	return bytes_written;
}

static int64_t FSWrite(FileHandle &handle, HANDLE hFile, void *buffer, int64_t nr_bytes, idx_t location) {
	int64_t bytes_written = 0;
	while (nr_bytes > 0) {
		auto bytes_to_write = MinValue<idx_t>(idx_t(NumericLimits<int32_t>::Maximum()), idx_t(nr_bytes));
		DWORD current_bytes_written = FSInternalWrite(handle, hFile, buffer, bytes_to_write, location);
		if (current_bytes_written <= 0) {
			throw IOException("Could not write file \"%s\": %s", {{"errno", std::to_string(errno)}}, handle.path,
			                  strerror(errno));
		}
		bytes_written += current_bytes_written;
		buffer = (void *)(data_ptr_cast(buffer) + current_bytes_written);
		location += current_bytes_written;
		nr_bytes -= current_bytes_written;
	}
	return bytes_written;
}

void LocalFileSystem::Write(FileHandle &handle, void *buffer, int64_t nr_bytes, idx_t location) {
	HANDLE hFile = handle.Cast<WindowsFileHandle>().fd;
	auto bytes_written = FSWrite(handle, hFile, buffer, nr_bytes, location);
	if (bytes_written != nr_bytes) {
		throw IOException("Could not write all bytes from file \"%s\": wanted=%lld wrote=%lld", handle.path, nr_bytes,
		                  bytes_written);
	}
}

int64_t LocalFileSystem::Write(FileHandle &handle, void *buffer, int64_t nr_bytes) {
	HANDLE hFile = handle.Cast<WindowsFileHandle>().fd;
	auto &pos = handle.Cast<WindowsFileHandle>().position;
	auto bytes_written = FSWrite(handle, hFile, buffer, nr_bytes, pos);
	pos += bytes_written;
	return bytes_written;
}

bool LocalFileSystem::Trim(FileHandle &handle, idx_t offset_bytes, idx_t length_bytes) {
	// TODO: Not yet implemented on windows.
	return false;
}

int64_t LocalFileSystem::GetFileSize(FileHandle &handle) {
	HANDLE hFile = handle.Cast<WindowsFileHandle>().fd;
	LARGE_INTEGER result;
	if (!GetFileSizeEx(hFile, &result)) {
		auto error = LocalFileSystem::GetLastErrorAsString();
		throw IOException("Failed to get file size for file \"%s\": %s", handle.path, error);
	}
	return result.QuadPart;
}

time_t LocalFileSystem::GetLastModifiedTime(FileHandle &handle) {
	HANDLE hFile = handle.Cast<WindowsFileHandle>().fd;

	// https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getfiletime
	FILETIME last_write;
	if (GetFileTime(hFile, nullptr, nullptr, &last_write) == 0) {
		auto error = LocalFileSystem::GetLastErrorAsString();
		throw IOException("Failed to get last modified time for file \"%s\": %s", handle.path, error);
	}

	// https://stackoverflow.com/questions/29266743/what-is-dwlowdatetime-and-dwhighdatetime
	ULARGE_INTEGER ul;
	ul.LowPart = last_write.dwLowDateTime;
	ul.HighPart = last_write.dwHighDateTime;
	int64_t fileTime64 = ul.QuadPart;

	// fileTime64 contains a 64-bit value representing the number of
	// 100-nanosecond intervals since January 1, 1601 (UTC).
	// https://docs.microsoft.com/en-us/windows/win32/api/minwinbase/ns-minwinbase-filetime

	// Adapted from: https://stackoverflow.com/questions/6161776/convert-windows-filetime-to-second-in-unix-linux
	const auto WINDOWS_TICK = 10000000;
	const auto SEC_TO_UNIX_EPOCH = 11644473600LL;
	time_t result = (fileTime64 / WINDOWS_TICK - SEC_TO_UNIX_EPOCH);
	return result;
}

void LocalFileSystem::Truncate(FileHandle &handle, int64_t new_size) {
	HANDLE hFile = handle.Cast<WindowsFileHandle>().fd;
	// seek to the location
	SetFilePointer(handle, new_size);
	// now set the end of file position
	if (!SetEndOfFile(hFile)) {
		auto error = LocalFileSystem::GetLastErrorAsString();
		throw IOException("Failure in SetEndOfFile call on file \"%s\": %s", handle.path, error);
	}
}

static DWORD WindowsGetFileAttributes(const string &filename) {
	auto unicode_path = NormalizePathAndConvertToUnicode(filename);
	return GetFileAttributesW(unicode_path.c_str());
}

static DWORD WindowsGetFileAttributes(const std::wstring &filename) {
	return GetFileAttributesW(filename.c_str());
}

bool LocalFileSystem::DirectoryExists(const string &directory, optional_ptr<FileOpener> opener) {
	DWORD attrs = WindowsGetFileAttributes(directory);
	return (attrs != INVALID_FILE_ATTRIBUTES && (attrs & FILE_ATTRIBUTE_DIRECTORY));
}

void LocalFileSystem::CreateDirectory(const string &directory, optional_ptr<FileOpener> opener) {
	if (DirectoryExists(directory)) {
		return;
	}
	auto unicode_path = NormalizePathAndConvertToUnicode(directory);
	if (directory.empty() || !CreateDirectoryW(unicode_path.c_str(), NULL) || !DirectoryExists(directory)) {
		auto error = LocalFileSystem::GetLastErrorAsString();
		throw IOException("Failed to create directory \"%s\": %s", directory.c_str(), error);
	}
}

static void DeleteDirectoryRecursive(FileSystem &fs, string directory) {
	fs.ListFiles(directory, [&](const string &fname, bool is_directory) {
		if (is_directory) {
			DeleteDirectoryRecursive(fs, fs.JoinPath(directory, fname));
		} else {
			fs.RemoveFile(fs.JoinPath(directory, fname));
		}
	});
	auto unicode_path = NormalizePathAndConvertToUnicode(directory);
	if (!RemoveDirectoryW(unicode_path.c_str())) {
		auto error = LocalFileSystem::GetLastErrorAsString();
		throw IOException("Failed to delete directory \"%s\": %s", directory, error);
	}
}

void LocalFileSystem::RemoveDirectory(const string &directory, optional_ptr<FileOpener> opener) {
	if (FileExists(directory)) {
		throw IOException("Attempting to delete directory \"%s\", but it is a file and not a directory!", directory);
	}
	if (!DirectoryExists(directory)) {
		return;
	}
	DeleteDirectoryRecursive(*this, directory);
}

void LocalFileSystem::RemoveFile(const string &filename, optional_ptr<FileOpener> opener) {
	auto unicode_path = NormalizePathAndConvertToUnicode(filename);
	if (!DeleteFileW(unicode_path.c_str())) {
		auto error = LocalFileSystem::GetLastErrorAsString();
		throw IOException("Failed to delete file \"%s\": %s", filename, error);
	}
}

bool LocalFileSystem::ListFiles(const string &directory, const std::function<void(const string &, bool)> &callback,
                                FileOpener *opener) {
	string search_dir = JoinPath(directory, "*");
	auto unicode_path = NormalizePathAndConvertToUnicode(search_dir);

	WIN32_FIND_DATAW ffd;
	HANDLE hFind = FindFirstFileW(unicode_path.c_str(), &ffd);
	if (hFind == INVALID_HANDLE_VALUE) {
		return false;
	}
	do {
		string cFileName = WindowsUtil::UnicodeToUTF8(ffd.cFileName);
		if (cFileName == "." || cFileName == "..") {
			continue;
		}
		callback(cFileName, ffd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY);
	} while (FindNextFileW(hFind, &ffd) != 0);

	DWORD dwError = GetLastError();
	if (dwError != ERROR_NO_MORE_FILES) {
		FindClose(hFind);
		return false;
	}

	FindClose(hFind);
	return true;
}

void LocalFileSystem::FileSync(FileHandle &handle) {
	HANDLE hFile = handle.Cast<WindowsFileHandle>().fd;
	if (FlushFileBuffers(hFile) == 0) {
		throw IOException("Could not flush file handle to disk!");
	}
}

void LocalFileSystem::MoveFile(const string &source, const string &target, optional_ptr<FileOpener> opener) {
	auto source_unicode = NormalizePathAndConvertToUnicode(source);
	auto target_unicode = NormalizePathAndConvertToUnicode(target);

	if (!MoveFileW(source_unicode.c_str(), target_unicode.c_str())) {
		throw IOException("Could not move file: %s", GetLastErrorAsString());
	}
}

FileType LocalFileSystem::GetFileType(FileHandle &handle) {
	auto path = handle.Cast<WindowsFileHandle>().path;
	// pipes in windows are just files in '\\.\pipe\' folder
	if (strncmp(path.c_str(), PIPE_PREFIX, strlen(PIPE_PREFIX)) == 0) {
		return FileType::FILE_TYPE_FIFO;
	}
	auto normalized_path = NormalizePathAndConvertToUnicode(path);
	DWORD attrs = WindowsGetFileAttributes(normalized_path);
	if (attrs != INVALID_FILE_ATTRIBUTES) {
		if (attrs & FILE_ATTRIBUTE_DIRECTORY) {
			return FileType::FILE_TYPE_DIR;
		} else {
			return FileType::FILE_TYPE_REGULAR;
		}
	}
	return FileType::FILE_TYPE_INVALID;
}
#endif

bool LocalFileSystem::CanSeek() {
	return true;
}

bool LocalFileSystem::OnDiskFile(FileHandle &handle) {
	return true;
}

void LocalFileSystem::Seek(FileHandle &handle, idx_t location) {
	if (!CanSeek()) {
		throw IOException("Cannot seek in files of this type");
	}
	SetFilePointer(handle, location);
}

idx_t LocalFileSystem::SeekPosition(FileHandle &handle) {
	if (!CanSeek()) {
		throw IOException("Cannot seek in files of this type");
	}
	return GetFilePointer(handle);
}

static bool IsCrawl(const string &glob) {
	// glob must match exactly
	return glob == "**";
}
static bool HasMultipleCrawl(const vector<string> &splits) {
	return std::count(splits.begin(), splits.end(), "**") > 1;
}
static bool IsSymbolicLink(const string &path) {
	auto normalized_path = LocalFileSystem::NormalizeLocalPath(path);
#ifndef _WIN32
	struct stat status;
	return (lstat(normalized_path, &status) != -1 && S_ISLNK(status.st_mode));
#else
	auto attributes = WindowsGetFileAttributes(path);
	if (attributes == INVALID_FILE_ATTRIBUTES)
		return false;
	return attributes & FILE_ATTRIBUTE_REPARSE_POINT;
#endif
}

static void RecursiveGlobDirectories(FileSystem &fs, const string &path, vector<string> &result, bool match_directory,
                                     bool join_path) {

	fs.ListFiles(path, [&](const string &fname, bool is_directory) {
		string concat;
		if (join_path) {
			concat = fs.JoinPath(path, fname);
		} else {
			concat = fname;
		}
		if (IsSymbolicLink(concat)) {
			return;
		}
		if (is_directory == match_directory) {
			result.push_back(concat);
		}
		if (is_directory) {
			RecursiveGlobDirectories(fs, concat, result, match_directory, true);
		}
	});
}

static void GlobFilesInternal(FileSystem &fs, const string &path, const string &glob, bool match_directory,
                              vector<string> &result, bool join_path) {
	fs.ListFiles(path, [&](const string &fname, bool is_directory) {
		if (is_directory != match_directory) {
			return;
		}
		if (Glob(fname.c_str(), fname.size(), glob.c_str(), glob.size())) {
			if (join_path) {
				result.push_back(fs.JoinPath(path, fname));
			} else {
				result.push_back(fname);
			}
		}
	});
}

vector<string> LocalFileSystem::FetchFileWithoutGlob(const string &path, FileOpener *opener, bool absolute_path) {
	vector<string> result;
	if (FileExists(path, opener) || IsPipe(path, opener)) {
		result.push_back(path);
	} else if (!absolute_path) {
		Value value;
		if (opener && opener->TryGetCurrentSetting("file_search_path", value)) {
			auto search_paths_str = value.ToString();
			vector<std::string> search_paths = StringUtil::Split(search_paths_str, ',');
			for (const auto &search_path : search_paths) {
				auto joined_path = JoinPath(search_path, path);
				if (FileExists(joined_path, opener) || IsPipe(joined_path, opener)) {
					result.push_back(joined_path);
				}
			}
		}
	}
	return result;
}

// Helper function to handle file:/ URLs
static idx_t GetFileUrlOffset(const string &path) {
	if (!StringUtil::StartsWith(path, "file:/")) {
		return 0;
	}

	// Url without host: file:/some/path
	if (path[6] != '/') {
#ifdef _WIN32
		return 6;
#else
		return 5;
#endif
	}

	// Url with empty host: file:///some/path
	if (path[7] == '/') {
#ifdef _WIN32
		return 8;
#else
		return 7;
#endif
	}

	// Url with localhost: file://localhost/some/path
	if (path.compare(7, 10, "localhost/") == 0) {
#ifdef _WIN32
		return 17;
#else
		return 16;
#endif
	}

	// unkown file:/ url format
	return 0;
}

const char *LocalFileSystem::NormalizeLocalPath(const string &path) {
	return path.c_str() + GetFileUrlOffset(path);
}

vector<string> LocalFileSystem::Glob(const string &path, FileOpener *opener) {
	if (path.empty()) {
		return vector<string>();
	}
	// split up the path into separate chunks
	vector<string> splits;

	bool is_file_url = StringUtil::StartsWith(path, "file:/");
	idx_t file_url_path_offset = GetFileUrlOffset(path);

	idx_t last_pos = 0;
	for (idx_t i = file_url_path_offset; i < path.size(); i++) {
		if (path[i] == '\\' || path[i] == '/') {
			if (i == last_pos) {
				// empty: skip this position
				last_pos = i + 1;
				continue;
			}
			if (splits.empty()) {
				//				splits.push_back(path.substr(file_url_path_offset, i-file_url_path_offset));
				splits.push_back(path.substr(0, i));
			} else {
				splits.push_back(path.substr(last_pos, i - last_pos));
			}
			last_pos = i + 1;
		}
	}
	splits.push_back(path.substr(last_pos, path.size() - last_pos));
	// handle absolute paths
	bool absolute_path = false;
	if (IsPathAbsolute(path)) {
		// first character is a slash -  unix absolute path
		absolute_path = true;
	} else if (StringUtil::Contains(splits[0], ":")) { // TODO: this is weird? shouldn't IsPathAbsolute handle this?
		// first split has a colon -  windows absolute path
		absolute_path = true;
	} else if (splits[0] == "~") {
		// starts with home directory
		auto home_directory = GetHomeDirectory(opener);
		if (!home_directory.empty()) {
			absolute_path = true;
			splits[0] = home_directory;
			D_ASSERT(path[0] == '~');
			if (!HasGlob(path)) {
				return Glob(home_directory + path.substr(1));
			}
		}
	}
	// Check if the path has a glob at all
	if (!HasGlob(path)) {
		// no glob: return only the file (if it exists or is a pipe)
		return FetchFileWithoutGlob(path, opener, absolute_path);
	}
	vector<string> previous_directories;
	if (absolute_path) {
		// for absolute paths, we don't start by scanning the current directory
		previous_directories.push_back(splits[0]);
	} else {
		// If file_search_path is set, use those paths as the first glob elements
		Value value;
		if (opener && opener->TryGetCurrentSetting("file_search_path", value)) {
			auto search_paths_str = value.ToString();
			vector<std::string> search_paths = StringUtil::Split(search_paths_str, ',');
			for (const auto &search_path : search_paths) {
				previous_directories.push_back(search_path);
			}
		}
	}

	if (HasMultipleCrawl(splits)) {
		throw IOException("Cannot use multiple \'**\' in one path");
	}

	idx_t start_index;
	if (is_file_url) {
		start_index = 1;
	} else if (absolute_path) {
		start_index = 1;
	} else {
		start_index = 0;
	}

	for (idx_t i = start_index ? 1 : 0; i < splits.size(); i++) {
		bool is_last_chunk = i + 1 == splits.size();
		bool has_glob = HasGlob(splits[i]);
		// if it's the last chunk we need to find files, otherwise we find directories
		// not the last chunk: gather a list of all directories that match the glob pattern
		vector<string> result;
		if (!has_glob) {
			// no glob, just append as-is
			if (previous_directories.empty()) {
				result.push_back(splits[i]);
			} else {
				if (is_last_chunk) {
					for (auto &prev_directory : previous_directories) {
						const string filename = JoinPath(prev_directory, splits[i]);
						if (FileExists(filename, opener) || DirectoryExists(filename, opener)) {
							result.push_back(filename);
						}
					}
				} else {
					for (auto &prev_directory : previous_directories) {
						result.push_back(JoinPath(prev_directory, splits[i]));
					}
				}
			}
		} else {
			if (IsCrawl(splits[i])) {
				if (!is_last_chunk) {
					result = previous_directories;
				}
				if (previous_directories.empty()) {
					RecursiveGlobDirectories(*this, ".", result, !is_last_chunk, false);
				} else {
					for (auto &prev_dir : previous_directories) {
						RecursiveGlobDirectories(*this, prev_dir, result, !is_last_chunk, true);
					}
				}
			} else {
				if (previous_directories.empty()) {
					// no previous directories: list in the current path
					GlobFilesInternal(*this, ".", splits[i], !is_last_chunk, result, false);
				} else {
					// previous directories
					// we iterate over each of the previous directories, and apply the glob of the current directory
					for (auto &prev_directory : previous_directories) {
						GlobFilesInternal(*this, prev_directory, splits[i], !is_last_chunk, result, true);
					}
				}
			}
		}
		if (result.empty()) {
			// no result found that matches the glob
			// last ditch effort: search the path as a string literal
			return FetchFileWithoutGlob(path, opener, absolute_path);
		}
		if (is_last_chunk) {
			return result;
		}
		previous_directories = std::move(result);
	}
	return vector<string>();
}

unique_ptr<FileSystem> FileSystem::CreateLocal() {
	return make_uniq<LocalFileSystem>();
}

} // namespace duckdb
